Bending machine for bending reinforcing irons for concrete

ABSTRACT

A bending machine for bending reinforcing iron rods for concrete, which includes electric control means for preselecting the bending angle of the bending dish or bending arm, in which each desired bending angle of the rod to be bent has associated therewith a setting potentiometer and all setting potentiometers are preceded by a dead angle advance potentiometer and by recoil potentiometers, said last mentioned two potentiometers which also may be combined to a unit being common to all of said setting potentiometers, while means are provided which are operable selectively to operatively connect any one of said setting potentiometers with said preceding dead angle advance potentiometer and said recoil potentiometer.

ilmted States Patent 1151 3,661,002 Peddinghaus, Jr. 1 May 9, 1972 [54] BENDING MACHINE FOR BENDING 3,156,287 11/1964 Munro ..72/s

REINFORCING IRONS FOR CONCRETE 3,512,383 5/1970 Arnold et al [72] Inventor: Paul Ferd Peddinghaus, Jr., Gevelsberg, p i E Ch -1 w L h ny Assistant Examiner-Michael .l, Keenan [73] Assignee: Paul Ferd Peddinghaus, Gevelsberg, Ger- A[mmey walter Becker many 57 ABSTRACT [22] Ffled: 1970 A bending machine for bending reinforcing iron rods for 2 App], 77 concrete, which includes electric control means for preselecting the bending angle of the bending dish or bending arm, in which each desired bending angle of the rod to be bent has as- [30] Foreign Application Priority Data sociated therewith a setting potentiometer and all setting 0C1v 4, 1969 Germany ..P 19 50 127.0 Pmenmmeters are priceded a dead angle advance P tlometer and by reco11 potennometers, sald last mentloned two potentiometers which also may be combined to a unit [52} US. Cl "72/21, 72/8, 72/217 being common to a of Said Semng Potentiometers, while [51] Int. Cl. ..B2lb 37/08, B2ld 7/02 means are provided which are operable Selectively to Opera [58] Fleld of Search "72/8, 221 tively connect any one of said setting potentiometers with said 72/217 preceding dead angle advance potentiometer and said recoil potentiometer. [56] References Cited 5 Claims, 3 Drawing Figures UNITED STATES PATENTS 3,352,136 11/1967 Clarke ..72/9

PATENTEDHAY 9 I972 3,661 002 INVENTOR, gal 7 ado/"r1744 03 I? BENDING MACHINE FOR BENDING REINFORCING IRONS FOR CONCRETE The present invention relates to a bending machine with electric adjustment of the bending angle of the bending dish or arm for bending reinforcing iron rods for concrete.

A great number of mechanical means for controlling the bending angle of the bending dish or arm of machines of the above mentioned type with left-hand or right-hand turning are known.

For purposes of facilitating the work and accelerating the operation of such machines with regard to these mechanical adjusting means, electrical control devices have been suggested for the bending angle. Such devices partly cooperate with abutments and limit switches. Moreover, also on the drive shaft there have been arranged freely rotatable contact discs which are adjustable by means of a control shaft and are arrestable. These contact discs have those surfaces which face each other each provided with a contact point and have their outer circumference each equipped with a collecting ring connected to the contact point by means of a conductor.

The control of the bending angle would also be possible by means of a potentiometer while the preselection of the desired bending angle could be effected by the potentiometer.

When bending a reinforcing iron rod for concrete, it has been found that the bending dish has to carry out a greater turn than corresponds to the desired bending angle. This is due to the fact that the bending dish or bending arm with its bending roll mounted thereon first has to carry out a dead angle or idling stroke from its zero position until the bending roll engages the iron rod.

This rotating movement which as dead angle stroke is to be carried out over a dead angle is followed by the bending angle proper at the end of which, however, the bending operation cannot yet be considered complete because, in conformity with the respective composition or character of the material and the strength of the iron rod, a recoil will occur which has also to be taken into consideration so that the bending dish must in addition to the dead angle and the desired bending angle also move over the recoil angle. If the dead angle or advance angle is designated as minus 01 and the desired bending angle is while the recoil angle is designated a it will be appreciated that the total angle a, over which the bending dish or bending arm has to move will be a, 04 a The dead angle a, and the recoil angle a are normally, in contrast to the desired bending angle at not immediately determined or ascertained angles (disregarding a table containing such values on the basis of numerous test bendings). It is rather necessary to ascertain the dead angle and the recoil angle by one or two test bending operations and a corresponding correction of these angles and thereby of the total turning angle of the bending dish or bending arm. This has been taken into consideration by mechanical means and, more specifically, by the application of an adjustable cam below the bending dish.

It is an object of the present invention to provide a device which will be relatively inexpensive and space-saving and while being easily adjustable and sturdy will be able to take into consideration the additional angle, i.e. the dead angle and the recoil angle.

This object and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIGS. 1 and 2 respectively diagrammatically illustrate the bending of a reinforcing iron rod and, more specifically, by 180 and 90.

F IG. 3 diagrammatically illustrates the control potentiometer and a dead angle potentiometer preceding the same as well as a recoil potentiometer.

The machine for bending iron rods according to the present invention is characterized primarily in that each desired bending angle of the iron rod has associated therewith a control potentiometer while all control potentiometers have in common a dead angle potentiometer and a recoil potentiometer or a composite potentiometer combining said two types of potentiometers. These potentiometers or this potentiometer are so arranged that each control potentiometer which becomes effective is to be connected with the dead angle and recoil potentiometer or with the composite potentiometer.

It has been found that generally the recoil angle pertaining to the various desired bending angles has a value which is substantially constant with bending angles from about 40 to 180, or the deviations from the desired bending angle are so minor that they can be considered admissible. Thus, against expectation, with the various bending angles, no variation in the angle to be added for the recoil has to be taken into consideration when the reinforcing iron rods remain of the same dimensions. Consequently, once the angle to be added has been set or adjusted, i. e. the dead angle and the recoil angle, all bending operations between 45 and 180 can be effected. This is accomplished by the preceding potentiometer or the composite potentiometer or by both.

The operator operating the bending machine for the reinforcing iron rods, therefore, in a simple manner and as customary heretofore, will adjust the desired bending angle of, for instance, 45, or and in conformity with his experience will adjust a preceding potentiometer or the two preceding potentiometers, in other words the recoil potentiometer and the dead angle potentiometer. If the bending angle does not meet the requirements, the operator will re-adjust one or both preceding potentiometers and thereupon will repeat the bending operation in order more precisely to ascertain the angle to be added and the respective adjustment. For reinforcing iron rods of identical thickness, the adjustment of the potentiometer for the angle to be added will during the bending of different angles be maintained.

Preferably with the setting of the bending angle, also the connection of the preceding potentiometer or potentiometers is effected. This may be brought about by connecting each setting potentiometer selectively through a common control rod to the dead angle potentiometer or the return potentiometer or to the combined potentiometers. The control rod may be displaceable in longitudinal direction and may be provided with serially arranged connecting contacts, or the control rod may, in a manner known per se, be rotatable about its longitudinal axis and may have its circumference at the level of the potentiometer equipped with connecting contacts. The connecting rod will then act as a control shaft.

Referring now to the drawings in detail, a counter roll 1 is arranged on the bending table of the machine or a perforated strip of the table, said counter roll 1 being adjustable in the direction of the arrow K. The bending dish carries at its center the shaping roll or shaping member 2 and furthermore in spaced relationship to the member 2 carries the bending roll 3 at the level of the marginal area of the bending dish. The bending roll 3 is in a manner known per se held on the bending dish by means of a stud and in response to the rotation of the bending dish or bending arm first carries out an advancing stroke which corresponds to the dead angle or, until the bending roll reaches its position 3 in which position it engages the end B of the reinforcing iron rod B. In this position, the reinforcing iron rod, on one hand, engages the rolls 1 and 3 and, on the other hand, engages the shaping roll or shaping member 2. Subsequently thereto, i. e. after moving through the angle 1.1: the bending dish with roll 3 moves through the angle a; which corresponds to the magnitude of the desired bending angle whereby roll 3 reaches its position 3".

Following the angle a roll 3 moves through an angle a which is determined by the recoil of the reinforcing iron rod. lf

the rotary stroke, after completion of the angles 0: and a were terminated, the reinforcing iron rod would be curved to an extent which would be less by an amount corresponding to the recoil. After passing through the angle a roll 3 reaches the position 3" so that the actual angle over which the bending dish or bending arm moves will equal the total of the angles 01, +01 +a =a When comparing FIGS. 1 and 2 with each other, it will be evident that with a bend of 90 and a bend of 180, assuming equal thickness of the rod and identical composition of the material, the recoil angle a and ([30 are against expectation approximately of the same magnitude. Since, however, with the same thickness of the rod the dead angles a, and a are equal, the angles of addition a, and a approximately equal the angles a and a Therefore, these angles must be set for a certain thickness of the rod and composition of its material and may be associated with each bending angle of from 45 to 180. To this end, each of the desired angles to be set, for instance, 45, 60, 90, 120, 150 and 180, respectively have associated therewith a control potentiometer 4, 5, 6, 7, 8, 9 (FIG. 3) which is provided with current conveying lines and 1 1.

Each of the control potentiometers 4 9 is adapted selectively to be preceded by a recoil potentiometer 11 and a dead angle potentiometer 12. Between the branch lines 13 of said potentiometers which branch lines are provided with corresponding contacts, and the contacts of the line 11 there is provided a control rod 14 with corresponding contacts 15 so that during the adjustment of the control rod 14 in longitudinal direction one of the control potentiometers 4 9 will be connected with the potentiometers 11 and 12. Instead of the control rod 14, also a corresponding control roll or drum may be provided. The two potentiometers 11 and 12 may be combined to a composite potentiometer which will take into consideration the angles a, and a It is, of course, to be understood that the present invention is, by no means, limited to the specific showing in the drawing but also comprises any modifications within the scope of the appended claims.

lclaim:

l. A bending machine for bending reinforcing iron rods for concrete, which comprises: a counter roll for supporting a portion of a rod to be bent, a forming member around which the rod is to be bent, a bending roll movable around the axis of said forming member, and control potentiometer means for controlling the movement of said bending roll and thereby the angle by which the iron rod will be bent, said control potentiometer means including a plurality of setting potentiometers for respectively setting the desired bending angle for the rod to be bent, a dead angle advance potentiometer common to said setting potentiometers, and a recoil potentiometer likewise common to said setting potentiometers, and control means operable selectively to correct any one of said setting potentiometers with both said dead angle advance potentiometer and said recoil potentiometer.

2. A bending machine according to claim 1, in which said control means includes a control rod common to all of said setting potentiometers.

3. A bending machine according to claim 2, in which said control rod is provided with a plurality of spaced connecting contacts arranged in series one behind the other in the longitudinal direction of said control rod, said control rod being displaceable in its longitudinal direction.

4. A bending machine according to claim 2, in which said control rod is rotatable and is provided with connecting contacts angularly distributed on said connecting rod for respective electrical engagement with said setting potentiometer.

5. A bending machine according to claim 1, in which said dead angle advance potentiometer and said recoil potentiometer are combined to one unit. 

1. A bending machine fOr bending reinforcing iron rods for concrete, which comprises: a counter roll for supporting a portion of a rod to be bent, a forming member around which the rod is to be bent, a bending roll movable around the axis of said forming member, and control potentiometer means for controlling the movement of said bending roll and thereby the angle by which the iron rod will be bent, said control potentiometer means including a plurality of setting potentiometers for respectively setting the desired bending angle for the rod to be bent, a dead angle advance potentiometer common to said setting potentiometers, and a recoil potentiometer likewise common to said setting potentiometers, and control means operable selectively to correct any one of said setting potentiometers with both said dead angle advance potentiometer and said recoil potentiometer.
 2. A bending machine according to claim 1, in which said control means includes a control rod common to all of said setting potentiometers.
 3. A bending machine according to claim 2, in which said control rod is provided with a plurality of spaced connecting contacts arranged in series one behind the other in the longitudinal direction of said control rod, said control rod being displaceable in its longitudinal direction.
 4. A bending machine according to claim 2, in which said control rod is rotatable and is provided with connecting contacts angularly distributed on said connecting rod for respective electrical engagement with said setting potentiometer.
 5. A bending machine according to claim 1, in which said dead angle advance potentiometer and said recoil potentiometer are combined to one unit. 